export function generateSubtractionSimplicity(difficulty: 1 | 2 = 1): {
  content: string;
  solution: string;
  difficulty: number;
  knowledge_code: string;
  question_type: string;
} {
  // 难度1: 后两个数相加为整十数
  // 难度2: 后两个数相加为整百数或包含零
  
  if (difficulty === 1) {
    const a = Math.floor(Math.random() * 100) + 50;
    const b = Math.floor(Math.random() * 40) + 10;
    const c = Math.floor(Math.random() * 40) + 10;
    const sumBC = b + c;
    return {
      content: `${a}-${b}-${c}`,
      solution: `${a}-${b}-${c} = ${a}-(${b}+${c}) = ${a}-${sumBC} = ${a - sumBC}`,
      difficulty,
      knowledge_code: '3.1.4_lian-jian-de-jianbian-jisuan',
      question_type: 'fill_in_blank'
    };
  } else {
    const a = Math.floor(Math.random() * 500) + 200;
    const b = Math.floor(Math.random() * 100) + 50;
    const c = Math.floor(Math.random() * 100) + 50;
    const sumBC = b + c;
    return {
      content: `${a}-${b}-${c}`,
      solution: `${a}-${b}-${c} = ${a}-(${b}+${c}) = ${a}-${sumBC} = ${a - sumBC}`,
      difficulty,
      knowledge_code: '3.1.4_lian-jian-de-jianbian-jisuan',
      question_type: 'fill_in_blank'
    };
  }
}